/* * w1-gpio - GPIO w1 bus master driver * * Copyright (C) 2007 Ville Syrjala * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include "../w1.h" #include "../w1_int.h" static u8 w1_gpio_set_pullup(void *data, int delay) { struct w1_gpio_platform_data *pdata = data; if (delay) { pdata->pullup_duration = delay; } else { if (pdata->pullup_duration) { gpio_direction_output(pdata->pin, 1); msleep(pdata->pullup_duration); gpio_direction_input(pdata->pin); } pdata->pullup_duration = 0; } return 0; } static void w1_gpio_write_bit_dir(void *data, u8 bit) { struct w1_gpio_platform_data *pdata = data; if (bit) gpio_direction_input(pdata->pin); else gpio_direction_output(pdata->pin, 0); } static void w1_gpio_write_bit_val(void *data, u8 bit) { struct w1_gpio_platform_data *pdata = data; gpio_set_value(pdata->pin, bit); } static u8 w1_gpio_read_bit(void *data) { struct w1_gpio_platform_data *pdata = data; return gpio_get_value(pdata->pin) ? 1 : 0; } #if defined(CONFIG_OF) static const struct of_device_id w1_gpio_dt_ids[] = { { .compatible = "w1-gpio" }, {} }; MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids); #endif static int w1_gpio_probe_dt(struct platform_device *pdev) { struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); struct device_node *np = pdev->dev.of_node; int gpio; pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) return -ENOMEM; if (of_get_property(np, "linux,open-drain", NULL)) pdata->is_open_drain = 1; gpio = of_get_gpio(np, 0); if (gpio < 0) { if (gpio != -EPROBE_DEFER) dev_err(&pdev->dev, "Failed to parse gpio property for data pin (%d)\n", gpio); return gpio; } pdata->pin = gpio; gpio = of_get_gpio(np, 1); if (gpio == -EPROBE_DEFER) return gpio; /* ignore other errors as the pullup gpio is optional */ pdata->ext_pullup_enable_pin = gpio; pdev->dev.platform_data = pdata; return 0; } static int w1_gpio_probe(struct platform_device *pdev) { struct w1_bus_master *master; struct w1_gpio_platform_data *pdata; int err; if (of_have_populated_dt()) { err = w1_gpio_probe_dt(pdev); if (err < 0) return err; } pdata = dev_get_platdata(&pdev->dev); if (!pdata) { dev_err(&pdev->dev, "No configuration data\n"); return -ENXIO; } master = devm_kzalloc(&pdev->dev, sizeof(struct w1_bus_master), GFP_KERNEL); if (!master) { dev_err(&pdev->dev, "Out of memory\n"); return -ENOMEM; } err = devm_gpio_request(&pdev->dev, pdata->pin, "w1"); if (err) { dev_err(&pdev->dev, "gpio_request (pin) failed\n"); return err; } if (gpio_is_valid(pdata->ext_pullup_enable_pin)) { err = devm_gpio_request_one(&pdev->dev, pdata->ext_pullup_enable_pin, GPIOF_INIT_LOW, "w1 pullup"); if (err < 0) { dev_err(&pdev->dev, "gpio_request_one " "(ext_pullup_enable_pin) failed\n"); return err; } } master->data = pdata; master->read_bit = w1_gpio_read_bit; if (pdata->is_open_drain) { gpio_direction_output(pdata->pin, 1); master->write_bit = w1_gpio_write_bit_val; } else { gpio_direction_input(pdata->pin); master->write_bit = w1_gpio_write_bit_dir; master->set_pullup = w1_gpio_set_pullup; } err = w1_add_master_device(master); if (err) { dev_err(&pdev->dev, "w1_add_master device failed\n"); return err; } if (pdata->enable_external_pullup) pdata->enable_external_pullup(1); if (gpio_is_valid(pdata->ext_pullup_enable_pin)) gpio_set_value(pdata->ext_pullup_enable_pin, 1); platform_set_drvdata(pdev, master); return 0; } static int w1_gpio_remove(struct platform_device *pdev) { struct w1_bus_master *master = platform_get_drvdata(pdev); struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); if (pdata->enable_external_pullup) pdata->enable_external_pullup(0); if (gpio_is_valid(pdata->ext_pullup_enable_pin)) gpio_set_value(pdata->ext_pullup_enable_pin, 0); w1_remove_master_device(master); return 0; } static int __maybe_unused w1_gpio_suspend(struct device *dev) { struct w1_gpio_platform_data *pdata = dev_get_platdata(dev); if (pdata->enable_external_pullup) pdata->enable_external_pullup(0); return 0; } static int __maybe_unused w1_gpio_resume(struct device *dev) { struct w1_gpio_platform_data *pdata = dev_get_platdata(dev); if (pdata->enable_external_pullup) pdata->enable_external_pullup(1); return 0; } static SIMPLE_DEV_PM_OPS(w1_gpio_pm_ops, w1_gpio_suspend, w1_gpio_resume); static struct platform_driver w1_gpio_driver = { .driver = { .name = "w1-gpio", .pm = &w1_gpio_pm_ops, .of_match_table = of_match_ptr(w1_gpio_dt_ids), }, .probe = w1_gpio_probe, .remove = w1_gpio_remove, }; module_platform_driver(w1_gpio_driver); MODULE_DESCRIPTION("GPIO w1 bus master driver"); MODULE_AUTHOR("Ville Syrjala "); MODULE_LICENSE("GPL"); r>commit0becc0ae5b42828785b589f686725ff5bc3b9b25 (patch) treebe6d0e1f37c38ed0a7dd5da2d4b1e93f0fb43101 /sound/synth/emux/emux.c parent24c2503255d35c269b67162c397a1a1c1e02f6ce (diff)
x86/mce: Make timer handling more robust
Erik reported that on a preproduction hardware a CMCI storm triggers the BUG_ON in add_timer_on(). The reason is that the per CPU MCE timer is started by the CMCI logic before the MCE CPU hotplug callback starts the timer with add_timer_on(). So the timer is already queued which triggers the BUG. Using add_timer_on() is pretty pointless in this code because the timer is strictlty per CPU, initialized as pinned and all operations which arm the timer happen on the CPU to which the timer belongs. Simplify the whole machinery by using mod_timer() instead of add_timer_on() which avoids the problem because mod_timer() can handle already queued timers. Use __start_timer() everywhere so the earliest armed expiry time is preserved. Reported-by: Erik Veijola <erik.veijola@intel.com> Tested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701310936080.3457@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'sound/synth/emux/emux.c')